CN117203134A - Cap for closing a dosing container and method for manufacturing the same - Google Patents

Abstract

A cap for closing a drug delivery container, comprising a can-shaped body having a cavity with at least one or more openings and a bottom plane for at least partially defining the cavity and at least one membrane, wherein the body has a dome with an opening on the end side, which opening is closed by the membrane, wherein the dome protrudes from the bottom plane on the side of the bottom plane opposite the cavity, wherein the membrane is inserted under prestress into a receiving cavity of the dome. And to a method of manufacturing such a cap.

Description

Cap for closing a dosing container and method for manufacturing the same

Technical Field

The present application relates to a cap for closing a drug delivery container and a method of manufacturing the same.

Background

Lids for closing drug containers, such as infusion bottles or infusion bags, are subject to many safety concerns, both concerning the tightness against escape of the drug and concerning the tightness against the ingress of media from the outside. In the context of further improvements, therefore, different design aspects often have to be considered.

A closure for a medicament container is known from EP2 376 A1, which closure has a receptacle spaced apart from the lid wall and directed inwardly from the bottom region of the lid in order to mechanically decouple the deformation forces acting on the outer wall. The outer wall of the cover protects the receptacle and its contents from external mechanical influences. At the same time, the diaphragm is held under prestress in the cap.

A disadvantage of the undercut, annular gap, etc. being internal in the area of the closure system in contact with the product is that the product does not remain there and if the cap is positioned with the membrane downwards, the product is not delivered to the patient.

In other variants of the prior art, dead volumes are created due to the shape of the diaphragm. Depending on the manner in which the diaphragm is inserted and secured in the cap, the diaphragm shapes may vary greatly from one another. In DE 10 2017 000 048 A1, fig. 7 and 8 show a general variant of a cap with a membrane, which has a circumferential annular groove 39 relative to the penetration region. Such annular grooves represent a dead volume in which liquid not delivered to the patient may collect. In another variant of fig. 9a and 9b, the membrane is constructed thick and protruding. Here too, in the bottom region between the puncture site and the cap edge, there is a dead volume created by design. However, the diaphragm shape of this document aims to ensure tightness of the cap and to minimize dead volume.

DE 10 2008 060 457 A1 has a variant of a cap in which the diaphragm is welded to the body of the cap without prestressing. However, due to the non-prestressed support of the membrane, the holding and sealing forces exerted on the liquid transfer device, such as the piercing member, are small. In this case, the shape of the piercing member is preferably needle-like, such as a needle or a spike. The sealing force and the holding force need to be increased.

As is known from DE 10 2017 000 048 A1, the sealing force increases with increasing radial prestress, which also disadvantageously results in an increase in the penetration force of the penetration piece. The radial prestress of the membrane, when assembled into the cap, must be such that the penetration length and thus the penetration resistance are selected that, on the one hand, the sealing and retaining function is improved, while, on the other hand, the penetration force can still be reduced. A saving in material and costs for the production of the membrane is also achieved by the features defined in the independent claims.

The seal between the cap and the diaphragm may be achieved in the diaphragm in different ways and methods. In DE 198 18314a1, the tightness of the diaphragm against the cover is achieved mainly by clamping the diaphragm in the cover by means of the clamping member 26.

DE 10 2016 003 253A1 belonging to this class shows a variant of a diaphragm with a sealing lip 16 encircling on the edge side, which sealing lip 16 transitions centrally into the sealing surface. In the variant of fig. 3b, such a sealing surface can have a planar course. However, the sealing lip 16 is solid in order to ensure sufficient prestress to achieve sufficient tightness and protrudes significantly with respect to the receiving cavity. Thus, a dead volume is formed in the intermediate space or dead space between the diaphragms and also between each diaphragm and the cover wall, as can be seen in fig. 2. In DE 10 compared with other diaphragms

2016 003 253a1 reduces but does not completely prevent the formation of dead volumes or dead spaces. This is necessary because the membrane is held in the cap in a force-locking manner without additional material locking, such as adhesive bonding or welding.

Disclosure of Invention

Starting from the prior art, the present application now aims to hold the diaphragm under prestress, but to avoid as much as possible the undercut (Hinterschnitte) and annular gap of the retained product in the body of the cap.

The application solves this problem by a cap having the features of claim 1 and a method having the features of claim 18.

A cap for closing a drug delivery container according to the present application comprises a can-like body having a cavity with at least one or more openings and a bottom plane for at least partially defining the cavity. The cavity may have openings, in particular on the sides of the outer circumferential surface, for example the conical outer circumferential surface, which are opposite each other, in order to enable, on the one hand, the entry of the medicament into the cavity and, on the other hand, the entry of the needle into the cavity after the penetration of the septum. An opening may be provided in the bottom region of the cover.

The body furthermore has a dome with an opening at the end side, which is closed by the membrane, wherein the dome protrudes from the bottom plane on the side of the bottom plane opposite the cavity. The opening in the bottom region of the lid may transition into another cavity within the dome. This cavity is closed outwards by a membrane. In the present application, no protection is provided against deformation forces acting from the outside, but the dome is exposed to these deformation forces. However, the active surface of the dome is small, so that the probability of deformation in this region is relatively low. However, the dosing of the infusion bag is at the same time more accurate, especially in case of overhead infusion where the infusion bag is suspended, because there is no undercut in the lid where the drug is retained. Furthermore, the cap may be used for various purposes if necessary.

The diaphragm is inserted under prestress into the receiving space of the dome. This allows the septum to be sealed after a single perforation and in particular after a plurality of perforations by means of a needle, injection needle or other element.

The prestressing force can be increased additionally by various structural design variants, so that the prestressing force is so great that even the deformation of the dome outer wall does not affect the tightness of the diaphragm.

The respective advantageous embodiments of the application, in particular the structural variants, are the subject matter of the dependent claims.

Advantageously, the diaphragm has an interference of at least 2.5%, preferably 3-10%, compared to the radially surrounding first inner surface of the receiving chamber. A diaphragm having a greater material thickness generally cannot cope with such a degree of interference fit. It is therefore advantageous if the axial extension of the region (in which the membrane has a closed surface over the width of the dome) extends over less than 70% of the height of the dome.

It is also advantageous for the prestress to be established by a force which is also such that the first inner surface has a conical course and preferably a course which deviates from the parallel course of the inner surface with respect to the central axis B of the dome by 3 to 10 °. This allows an additional retaining effect of the diaphragm and enables a higher sealing force to be achieved over the height of the diaphragm than a diaphragm having a cylindrical basic shape. The diaphragm allows approximately the same amount of sealing force and the same stress level to be established at the level of the receptacle under prestress.

In addition, the thickness of the septum or the penetration length in the septum may be reduced. Thus requiring lower penetration force and reducing tearing of the material during penetration.

For tightness, it is particularly preferred to arrange a material-locking connection between the membrane and the body, for example as a welded connection or an adhesive connection. Such a material-locking connection can particularly preferably be embodied as a welded connection, particularly preferably a welded connection which in this case surrounds radially about the central axis B of the dome. Apart from the force-locking and material-locking connection of the diaphragm and the dome by prestressing, this welded connection then forms a second safety measure, the so-called "second line of defense", preventing the escape of the medicament or the ingress of the medium.

Particularly preferably, the welded connection is positioned such that a radial tensile force acts on the membrane as soon as a puncture is made. This is advantageous because the material displacement that occurs in the case of thick diaphragms can thus be compensated for by the pulling movement. Such radial pulling forces occur in particular when the diaphragm is welded to the body in an axial direction with respect to its own diaphragm central axis or diaphragm longitudinal axis.

The diaphragm can be made of a thermoplastic elastomer, in particular because it can be welded and is particularly well suited to build up prestress due to its elastic properties. Individual sections of the diaphragm, e.g. individual layers, may also be made of different materials, but at least the contact surface on the dome where the welding takes place should preferably be made of TPE material. However, it is particularly preferred that the entire diaphragm is also made of TPE.

The cap may have a radially encircling second inner surface defining said receiving chamber, which has a smaller average diameter than the radially encircling first inner surface. There may also be a pre-stress between the body and the diaphragm. In this case, it is advantageous if the diaphragm has a smaller interference with respect to the radially encircling second inner surface than with respect to the radially encircling first inner surface.

Alternatively or additionally, the radially encircling second inner surface may deviate by a greater angle with respect to the parallel course with respect to the central axis of the dome than the radially encircling first inner surface.

The membrane may in particular have a prestress gradient along the central axis of the dome, which may particularly preferably increase in the penetration direction. Whereby no crater is left in the septum after removal of the needle.

The material-locking connection may preferably be arranged between the radially encircling first and second inner surfaces. Whereby the anchoring point of the membrane of the cap is located between two substantially equally active prestressing areas.

The cylindrical contour of the receptacle of the diaphragm, or of the surface in which the diaphragm rests with interference on the cover, and as it is known from the prior art, has a prestress reduction along the wall due to the lever length, so that very thick diaphragms must be used. This is particularly disadvantageous because of the material consumption and the increased force required to perform the piercing.

By means of the conical profile and/or an optimal positioning of the anchoring point in the form of a welding or adhesive point between the two relatively short lever arms, a better force distribution of the prestressing force and thus a better sealing effect can be achieved in the sealing region. Thus, in turn, the thickness of the diaphragm may be minimized at the same time.

It is particularly preferred that the cover has two domes with the same contour. This may result in significant material savings, especially in improving the sealing effect while reducing the thickness of the diaphragm.

Advantageously, the membrane may have a closed sealing surface extending over the width of the membrane, from which sealing surface radially encircling tabs protrude, which tabs, unlike EP2 376 3411 a1, are not mechanically decoupled from the outer wall of the cap, but form part of the radially encircling outer surface of the membrane which is in contact with the inner surface of the dome. The tab is thus supported on the side wall of the dome and acts as a spring arm to establish an axial restoring force when the diaphragm is axially deformed. However, the deformation of the wall of the dome here also directly leads to the deformation of the webs.

The body may be made of a thermoplastic material, preferably PP or PE, especially HDPE.

Furthermore, according to the application, a method for producing a cap according to the application is provided, which comprises the following steps:

a provides a body, in particular according to any of the preceding claims;

b inserting a diaphragm into the body, in particular by contact pressure;

c forming a material-locking connection between the membrane and the body, in particular while at least partially maintaining the contact pressure,

a cap with a seal is thereby achieved by prestressing and by a material-locking connection. The material-locking connection is reliably sealed against lateral escape of the medicament, while in addition to the edge-side sealing, the prestressing also assists in resealing the membrane after its perforation.

Drawings

One embodiment variant of the cap according to the application is described in more detail below. The drawings show:

fig. 1 shows a cross-sectional view of one embodiment variant of a cap according to the application;

fig. 2 shows a top view of a cap according to the present application.

Detailed Description

Fig. 1 and 2 show a cap 1 for closing a container, not shown in detail, such as an infusion bottle or an infusion bag.

The cap 1 has a body 25, preferably made of a first thermoplastic material, in particular polypropylene PP and/or polyethylene PE, in particular FIDPE.

The body 25 is configured to be substantially shape stable. The body 25 has a pot-like basic shape with a cavity 24 typically open for such a shape. The opening 27 is used here for inserting or fitting the cap into a corresponding container, for example a bottle or a bag. The cavity 24 is delimited by a conical first wall section 6, the first wall section 6 defining a cover central axis a. The conical shape of the wall section deviates from the cylindrical shape by less than 5 °, preferably between 1 and 3 °. This enables a contact pressure to be applied to the container.

The conical first wall section 6 ends with a base plate 5 on the base plane 4. Depending on the shape of the counterpart on the container corresponding to the lid 1, the bottom plane 4 may be defined by the bottom plate 5 and form a closed plane with respect to the container. However, the base plate 5 does not have to be arranged perpendicular to the wall sections 6, but the wall sections 6 are transitioned into the base plate 5 by means of circumferential edges, bends or rounds, so that at least the circumferential edges, bends or rounds lie on the base plane 4, thereby defining the position of the base plane 4. In other words, the circumferential, preferably circular circumferential line formed by the edge, the curvature or the rounded apex can lie on the bottom plane 4 at half the wall thickness of the edge.

Starting from the bottom plane 4, the cavity 24 of the lid has no protrusions or undercuts in the direction of the interior space of the lid, so that no scale forms, for example when the components of the medicament, which are usually in the form of a solution, form crystals.

Starting from the bottom plane 4, the body 25 has a receiving geometry for the two diaphragms 2 above the cavity 24 delimited by the first wall section 6. The transition from the base plate 5 to the receiving geometry is stepped in this case. The membrane is made of a second material, which has a lower hardness than the body 2, so that the membrane can be pierced by conventional means of medical technology. Such a material is particularly preferably TPE, i.e. a thermoplastic elastomer.

In fig. 1, the receiving geometry of the body 25 comprises two domes 26 connected to one another by a web 9, which protrude from the bottom plane 5 or from the side of the bottom plate 5 remote from the cavity 24. The tab 9 has a recess in the form of a channel 23. Of course, in a modification of the application, only one dome may be constructed.

Each dome 26 defines a central dome axis B and delimits a receiving space 20 for a respective diaphragm 2, wherein the receiving space is open on both sides in the axial direction with respect to the central dome axis B.

The first opening 15 of the receiving chamber 20 represents a transition into the cavity 24 and the second opening 17 is closed by the membrane 2. As can be seen from fig. 1, the sum of the average diameters of the two receiving cavities of dome 26 is less than the average diameter of cavity 24.

Each dome 26 also has a radially encircling first conical inner surface 16 defining a receiving cavity for receiving the diaphragm 2. The tapered surrounding inner surface 16 defines the average diameter as the average of all the diameters above the contact area of the inner surface with the diaphragm.

In contrast, the respective diaphragm 2 has an interference of at least 2.5%, preferably 3-10%, in the contact area with the first inner surface 16. The interference is shown in figure 1 by reference numeral 3. The membrane 2 has in particular a radially encircling first conical outer surface 13, which defines an average diameter. The difference between the diameter of the outer surface 13 of the diaphragm 2 (in the disassembled state) and the diameter of the inner surface 16 of the dome 26 defines said interference 3, so that the average diameter of the outer surface 13 of the diaphragm 2 in the disassembled state is at least 2.5% larger than the diameter of the inner surface 16 of the dome 26.

The inner surface 16 here comprises the largest contact surface between the diaphragm 2 and the dome 26. The second opening 17 defines a sealing plane 50. Drug escape should be prevented along this sealing plane 50.

The dome 26 comprises a stepped transition 7, which stepped transition 7 has a radially encircling second conical inner surface 11 of the dome, which ends in the opening 17. In contrast, the outer surface 12 of the respective membrane 2 has an interference 18 of at least 2.5%, preferably 3-10%, in the contact area with the second inner surface 11, wherein the interference 18 refers to the disassembled state of the membrane 2.

The radially encircling second conical inner surface 11 has a greater taper, i.e. a greater deviation from the course of the parallel-extending cylindrical shape, than the radially encircling first conical inner surface 16. Preferably, the interference may be smaller than in the region of the first inner surface 16, so that a progressive prestressing force is established in the course of the central axis of the dome. This allows an initial displacement of the material of the membrane 2 outwards in the region of the puncture, but at the same time a sealing effect can also be achieved in this region.

The stepped transition 7 of the dome 26 comprises a surface section 10 extending substantially parallel to the sealing plane 50. The surface section 10 can also have an inclined course, in particular a conical course. The surface section 10 has a material-locking connection between the dome 26 and the membrane 2.

The material-locking connection in the surface section 10 is preferably a welded connection. The welded connection can be produced by laser welding, wherein the laser beam is directed onto the outer surface of the cap 1 forming the sealing plane 50, in particular the end face 8 of the cap 1, which has advantages in terms of manufacturing technology and sealing effect.

In the region of the surface section 10, the diaphragm rests substantially without prestress on the inner surface of the dome 26. Thereby reducing material stress during welding, thereby enhancing sealing effect and preventing material separation.

The diaphragm 2 has a closed sealing surface 19 facing the cavity 24 and extending over the width of the diaphragm. From which radially encircling webs 14 protrude, the radially encircling webs 14 forming part of the radially encircling outer surface of the diaphragm 2 in contact with the dome inner surface 16. As can be seen directly from fig. 1, the sealing surface 19 has a planar, in particular completely planar, course in the region between the radially encircling webs 15.

Fig. 1 also shows that such a plane-oriented width of the sealing surface 19 occupies significantly more than 50% of the total width of the membrane 2.

As can also be seen from fig. 1, the tab 14 rests against the inner surface 16 of the dome 26 and ends flush with the receiving cavity 20 of the dome 26.

The dome 26 protrudes relative to the base plate 5, wherein the receiving space 20 of the dome 26 extends according to fig. 1 up to the inner surface of the base plate 5 facing the cavity 24.

The webs 14 increase the sealing effect of the membrane 2 in the edge region and allow a high prestress to be built up, wherein the free space between the opposing sections of the webs 14 can also be used for material displacement, for example when a needle penetrates into the membrane. The sections of the tabs 14 simultaneously act as spring arms when the septum is deformed in the axial direction, for example when a larger injection needle penetrates into the septum. A restoring force is thereby generated in the axial direction, so that, when the needle is removed, in addition to the radial prestress, the axial component also acts to close the puncture site.

The radial average width of the tabs may preferably be less than 50%, preferably less than 35%, of the axial height of the outer surface of the diaphragm 2 in contact with the inner surface 16 of the dome 26.

The taper of the second inner surface 16 of the dome 26 is also smaller than the taper of the first inner surface 11, so that a different, in particular smaller, prestress is also thereby created in the upper region of the membrane 2 than in the lower region during puncturing in the membrane 2, wherein the "upper" and "lower" here are based on the puncturing direction E and the position of the puncturing sealing surface 50.

Not shown in fig. 1 is the connection of the tab 9 between the two diaphragms 2 to the base plate 5 in the plane of illustration. In general, the oval basic shape of the entire receiving geometry, including the dome 26, is formed in the top view of the cap in the piercing direction.

The lid 1 shown in fig. 1 is shown in an ideal manner. The sealing plane 50 is defined here by the opening edge of the opening 17. In fact, the end face of the membrane, which is substantially perpendicular to the penetration direction, may be slightly curved with respect to the sealing plane due to the prestressing force.

Furthermore, the application also relates to a method for producing the above-described cap 1. The method comprises a first step in which the body 25 is provided. The body 25 may be manufactured, for example, by an injection molding process or by other suitable plastic processing processes.

In a second step of the method, the diaphragm 2 can be inserted into the housing cavity 20 of the dome 26 of the body 25. Such insertion may be accomplished by pressing the diaphragm with a contact pressure.

Such contact pressure can be maintained at least partially in a subsequent step, in which a material-locking connection is formed between the respective membrane 2 and the body 25. Such a material-locking connection is preferably formed on the surface section 10 by means of a welded connection. This may be achieved by laser welding.

The membrane, or sealing plane, may then be covered by a cover element 22, such as a plastic film or an aluminum foil or a plastic molded body, which may be part of the lid. This can be seen, for example, in the top view of fig. 2.

The lid may then be packaged under aseptic conditions.

List of reference numerals

1. Cover

2. Diaphragm

3. Interference magnitude

4. Bottom plane

5. Bottom plate

6. Wall section

7. Stepped transition

8. End face of cover

9. Tab

10. Surface section

11. A second conical inner surface

12. Second tapered outer surface of diaphragm

13. First tapered outer surface of diaphragm

14. Surrounding tab

15. A first opening

16. A first conical inner surface

17. A second opening

18. Interference magnitude

19. Sealing surface

20. Accommodating chamber

21. Annular tab

22. Covering element

23. Channel(s)

24. Cavity cavity

25. Body

26. Vault

27. An opening

50. Sealing plane

Longitudinal axis of A cover

Central axis of vault B

E puncture direction.

Claims (23)

1. Lid (1) for closing a dosing container, comprising a can-shaped body (25) having a cavity (24), the cavity (24) having at least one or more openings (15, 27) and a bottom plane (4) for at least partially defining the cavity (24) and at least one membrane (2), wherein the body (25) has a dome (26), the dome (26) having an end-side opening (17), the opening (17) being closed by the membrane (2),

wherein the dome (26) protrudes from the bottom plane (4) on the side of the bottom plane (4) opposite the cavity (24), wherein the membrane (2) is inserted under prestress into a receiving cavity (20) of the dome (26),

it is characterized in that the method comprises the steps of,

a material locking connection is arranged between the diaphragm (2) and the body (25),

and wherein the material-locking connection is arranged between a radially encircling first and a second inner surface (11 and 16), wherein the diaphragm (2) has a closed sealing surface (19) extending over the width of the diaphragm (2), and a radially encircling tab (14) protrudes from the sealing surface (19), the tab (14) forming a part of a radially encircling outer surface (13) of the diaphragm (2) in contact with the first inner surface (16) of the dome (26), and the sealing surface (19) having a planar course in the region between the radially encircling tabs (14).

2. Cap according to claim 1 or 2, wherein the tab (14) has a radial average width less than 50%, preferably less than 35%, of the axial height of the outer surface of the diaphragm (2) in contact with the inner surface (16) of the dome (26).

3. Cap according to any one of the preceding claims, wherein the dome (26) protrudes with respect to the base plate (5), wherein the receiving cavity (20) of the dome (26) extends up to the inner surface of the base plate (5) facing the cavity (24).

4. Cap according to any one of the preceding claims, wherein said tab (14) rests on the inner surface (16) of said dome (26) and terminates flush with said containing cavity (26).

5. Cap according to any of the preceding claims, wherein the material-locking connection is a welded connection, preferably a welded connection that surrounds radially around the centre axis (B) of the dome.

6. Cap according to any of the preceding claims, wherein the welded connection is positioned such that a radial pulling force is exerted on the membrane (2) whenever a piercing is performed.

7. Cap according to any of the preceding claims, wherein the material-locking connection is arranged between the radially encircling first and second inner surfaces (11 and 16), preferably in a stepped transition (7).

8. Cap according to claim 7, wherein the end-side opening (17) defines a sealing plane, wherein the stepped transition (7) of the dome (26) has a surface section (10) extending substantially parallel to the sealing plane (50) of the membrane, wherein the surface section (10) has the material-locking connection between the dome (26) and the membrane (2).

9. Cap according to claim 8, wherein the material-locking connection is a laser-welded connection, which can be produced by directing a laser beam onto the outer surface of the cap forming the sealing plane (50).

10. Cap according to any one of the preceding claims, wherein the membrane (2) rests without prestress on the inner surface of the dome (26) in the region of the surface section (10).

11. Cap according to any one of the preceding claims, wherein the membrane (2) has an interference (3) of at least 2.5%, preferably 3-10%, compared to a radially surrounding first inner surface (16) of the containing cavity (20).

12. Cap according to any one of the preceding claims, wherein the radially encircling first inner surface (16) of the dome (26) has a conical course, preferably a course which deviates from the parallel course of the inner surface with respect to the central axis (B) of the dome by 3-10 °.

13. Cap according to any one of the preceding claims, wherein said membrane (2) is made of thermoplastic elastomer.

14. Cap according to any one of the preceding claims, wherein the cap (1) has a radially encircling second inner surface (11) for defining the containing cavity (20), the average diameter of which is smaller than the radially encircling first inner surface (16).

15. Cap according to any one of the preceding claims, wherein the membrane (2) has a smaller interference with respect to the radially surrounding second inner surface (11) than with respect to the radially surrounding first inner surface (16).

16. Cap according to any one of the preceding claims, wherein the cap (1) has two identical domes (16).

17. Cap according to any of the preceding claims, wherein the cap (1) has two membranes (2) of identical profile.

18. Cap according to any one of the preceding claims, wherein the radially encircling second inner surface (11) deviates from a parallel orientation with respect to the central axis of the dome by a greater angle than the radially encircling first inner surface (16).

19. Cap according to any one of the preceding claims, wherein said membrane (2) has a pre-stress gradient along said central axis of vault (B).

20. Cap according to any one of the preceding claims, wherein the body (25) is made of thermoplastic material, preferably PP or PE, in particular HDPE.

21. Cap according to any one of the preceding claims, wherein the height of the dome (26) is less than 30%, preferably between 10-25%, of the total height of the cap (1).

22. Cap according to any of the preceding claims, characterized in that the cavity (24) of the cap (1) is free of protrusions or undercuts in the plane defined by the bottom plate (5) in order to avoid scaling, in particular when the components of the medicament form crystals.

23. Method for manufacturing a cap (1) according to any of the preceding claims, characterized by the steps of:

a provides a body (25), in particular according to any one of the preceding claims;

b inserting a membrane (2) into the body (25), in particular in the case of contact pressure;

c form a material-locking connection between the diaphragm (2) and the body (25), in particular while at least partially maintaining the contact pressure, wherein the material-locking connection is configured as a welded connection by means of laser welding, wherein a laser beam is directed onto the outer surface of the cap 1 forming the sealing plane (50).